ID

E*

${\text{PERM}}_{{t}_{exp}}$

REMC_{
pm
}

REMC_{
m
}


L113

16

16 (120 sec)

16 (6 sec)

16 (6 sec)

L122

16

16 (57 sec)

16 (3 sec)

16 (2 sec)

L131

16

16 (28 sec)

16 (3 sec)

16 (3 sec)

L115

24

24 (100 hrs†)

24 (17 min)

24 (14 min)

L124

24

24 (49 hrs†)

24 (9 min)

24 (7 min)

L133

24

23

24 (7 min)

24 (5 min)

L142

24

24 (49 hrs†)

24 (5 min)

24 (4 min)

L137

40

38

38 (20 hrs)

38 (20 hrs)

L155

40

38

38 (16 hrs)

38 (14 hrs)

L182

40

38

38 (16 hrs)

38 (14 hrs)

 The L1structures proposed in [52] are the most difficult stable structures for REMC to fold. Both PERM and REMC are unable to find the optimal conformations for L137, L155, and L182 after 100, one hour runs. PERM also did not find the optimal conformation for L133. When only one folding direction of PERM finds the optimal conformation, we report the mean runtime of that direction, denoting this in the table with a †. When best energies found by ${\text{PERM}}_{{t}_{1}}$ and ${\text{PERM}}_{{t}_{2}}$ differed (and neither find the optimal solution), the best energy by either is reported and the runtime is omitted. For every instance, 100 independent runs were conducted of 1 CPU hour each. In cases where not every run reached the same energy value after 1 hour, the expected runtime to reach the energy value shown in the table was calculated using the equation detailed by Parkes and Walser [54].